High contrast light sensitive materials

ABSTRACT

PHOTOGRAPHIC ELEMENTS COMPRISING A SUPPORT COATED WITH A HYDROPHILIC LAYER CONTAINING A FINE GRAIN, HIGH CONTRAST SILVER HALIDE EMULSION THAT IS ORTHOCHROMATICALLY SENSITIZED WITH A DECOLORIZABLE SPECTRAL SENSITIZING DYE THAT PRODUCES A MODICUM OF SENSITIVITY IN THE RED REGION OF THE SPECTRUM, SAID ELEMENTS HAVING POOR TOLERANCE TO RED SAFELIGHT ARE MADE TOLERANT TO RED SAFELIGHT BY INCORPORATING IN THE HYDROPHILIC COLLOID LAYER WITH OR ABOVE THE SILVER HALIDE, A WATER-SOLUBLE ANTHRAQUINONE DYE WHICH HAS SUBSTANTIALLY NO ABSORPTION OF LIGHT IN THE BLUE AND GREEN REGIONS OF THE SPECTRUM BUT STRONGLY ABSORBS LIGHT IN THE RED REGION OF THE SPECTRUM, WITHOUT ADVERSELY AFFECTING THE QUALITY OFTHE DEVELOPED, HIGH CONTRAST IMAGES OR LEAVING ANY APPRECIABLE STAIN IN THE PROCESSED ELEMENT.

United States Patent 9 US. Cl. 96-94 16 Claims ABSTRACT OF THEDISCLOSURE Photographic elements comprising a support coated with ahydrophilic colloid layer containing a fine grain, high contrast silverhalide emulsion that is orthochromatically sensitized with adecolorizable spectral sensitizing dye that produces a modicum ofsensitivity in the red region of the spectrum, said elements having poortolerance to red safelight are made tolerant to red safelight byincorporating in the hydrophilic colloid layer with or above the silverhalide, a watersoluble anthraquinone dye which has substantially noabsorption of light in the blue and green regions of the spectrum butstrongly absorbs light in the red region of the spectrum, withoutadversely affecting the quality of the developed, high contrast imagesor leaving any appreciable stain in the processed element.

This invention relates to improved photographic elements and includesphotographic elements containing ortho-sensitized high contrast silverhalide emulsions having improved safelight tolerance.

Photographic films used in the graphic arts for making half-tone or lineimages should be capable of producing extremely high contrast and goodimage sharpness. These factors contribute in the case of half-toneimages to high quality, that is, to the production of half-tone dots ofhigh density and sharpness. Photographic elements of the lith-type, thatis, elements having a fine grain high contrast silver halide emulsioncontaining at least 60 mole percent chloride, less than 40 mole percentbromide and less than about 5 mole percent iodide are especiallyefficacious for use in the graphic arts where high dot quality isrequired. These elements usually require the use of pure hydroquinonedeveloper solutions having very low sulfite ion concentration in thealkaline solution in order to produce the high contrast and high dotquality required for good quality half-tone reproduction. The knownphotographic films used in the graphic arts usually are relatively slowin speed and require relatively long exposure even when very highintensity light sources are used. It is, therefore, desired tospectrally sensitize these photographic emulsions so that the greenlight in the light source as well as the blue light will be recorded.Spectral sensitizing dyes which have been tried in these emulsions forortho-sensitizing them have left undesirable stains in the processedelement. Other spectral sensitizing dyes which have left relativelylittle, if any, stain in the processed elements have produced anundesirable sensitivity in the red region of the spectrum. This hasproduced problems because it has always been the practice of those usinggraphic arts photographic materials to develop the exposed film underenough red light so that the quality of the developing image could beobserved and the length of development controlled to give optimumquality. The undesirable red light sensitivity produced by availablegreen light-sensitizing dyes which produce little, if any, stain in theprocessed photographic materials has made it impractical to use redsafelights to follow the develop ment as has been the practice. Improvedphotographic elements are therefore desired for use in the graphic artswhich are ortho-sensitized and which can be processed under redsafelights.

It is an object of my invention to provide improved high contrast finegrain photographic silver halide emulsions which are ortho-sensitizedbut have improved safelight tolerance.

It is another object of my invention to provide improved photographicelements for use in the graphic arts to produce extremely high contrastimages and good image sharpness with little, if any, stain in theprocessed element, the said emulsion being ortho-sensitized and capableof being handled and developed safely under conventional red safelightsused in the graphic arts.

Still other objects Will become apparent from the followingspecification and claims.

These and other objects are accomplished according to my invention byproviding photographic elements containing my ortho-sensitized highcontrast fine grain silver halide emulsion in which the silver halidecontaining at least about 60 mole percent chloride, less than about 40mole percent bromide and less than about 5 mole percent iodide which hasa modicum of sensitivity in the red region of the spectrum, and aWater-soluble anthraquinone dye which has substantially no absorption oflight in the blue and green regions of the spectrum but which stronglyabsorbs light in the red region of the spectrum and which producessubstantially no change in quality of high contrast images produced bydevelopment of latent images in my silver halide emulsions. By modicumof sensitivity in the red region of the spectrum, I mean a minor amountof sensitivity which will produce an undesirable amount of fog in a highcontrast fine grain silver halide emulsion from prolonged exposure to ared safelight followed by the usual photographic development. Theanthraquinone dye is advantageously incorporated in the photographicemulsion layer since it has substantially no sensitizing effect on thesilver halide emulsion or alternatively it is advantageously coated in alayer over the silver halide emulsion layer or even under the silverhalide emulsion layer since the anthraquinone dye is water-soluble anddiffuses readily from one layer to the next layer.

My photographic elements have good tolerance to exposure to redsafelights and the processed element contains little, if any, residualstain from the spectral sensitizing dye and substantially no stain fromthe anthraquinone dye. Any of the conventional processes can be used toadvantage for processing my photographic elements.

The fine grain silver halide emulsions used to advantage are highcontrast emulsions which when developed in high contrast developers,such as, an amine developer in a roller transport system as described inBelgian Patent 704,595, produce a contrast in the range from about 2 toabout 20 measured at a density of 0.10 above gross fog over a range of0.40 log E with a gradient meter. The emulsions have silver halidecrystals, preferably containing at least about 60 mole percent chloride,less than about 40 mole percent bromide and less than about 5 molepercent iodide. A preferred emulsion contains at least about percentchloride in the silver halide. The emulsions are advantageously preparedas described by MacWilliam US. Patent 2,756,148, issued July 24, 1956.

The silver halide is dispersed in hydrophilic colloid materials used asbinders, including gelatin, colloidion, gum arabic, cellulose esterderivatives, such as, alkyl esters of carboxylated cellulose, hydroxyethyl cellulose, carboxy methyl cellulose, hydroxy ethyl cellulose,synthetic resins, such as the amphoteric copolymers described by Clavieret al. in US. Patent 2,949,442, issued Aug. 16, 1960, polyvinyl alcohol,and others well known in the art. Examples of these polymeric gelatinsubstitutes are copolymers of allylamine and methacrylic acid;copolymers of allylamine, acrylic acid and acrylamide; hydrolyzedcopolymers of allylamine, methacrylic acid and vinyl acetate;

the copolymers of allylamine, acrylic acid and styrene; the copolymersof allylamine, methacrylic acid and acrylonitrile; alkylacrylate-acrylic acid copolymers, e.g., cpolymers of butylacrylate-acrylic acid, etc.

It is advantageous to add certain onium salts, such as, quaternaryammonium salts, sulfonium salts and phosphonium salts to mylight-sensitive emulsions in order to increase the photographic speedwithout adversely affecting the dot quality, contrast and evenness ofdevelopment. Examples of quaternary ammonium salts include nonylpyridinium perchlorate, hexoxymethyl pyridinium perchlorate, ethylenebis-dioxymethyl pyridinium perchlorate and others described by CarrollU.S. Patent 2,271,- 623, issued February 3, 1942,hexadecamethylene-1,16- bis(pyridinium perchlorate),9,16-diaza-7,18-dioxa-8,17- dioxotetracosane-1,2,4-bis(pyridiniumperchlorate), and others of Beavers et a1. U.S. Patent 2,944,898, issuedJuly 12, 1960. Other examples include the onium salts ofpolyoxyalkylenes of Carroll et al. U.S. Patent 2,944,- 902, issued July12, 1960, the polyonium salts of Carroll et al. U.S. Patent 2,288,226,issued June 30, 1942, such as bis(lauryl methyl sulfonium p-toluenesulfonate) l,2 ethane, N,N'-trimethylene dioxymethyl pyridiniumperchlorate, etc., the sulfonium salts of Carroll et a1. U.S. 2,275,727,issued Mar. 10, 1942, such as, n-decyl dimethyl sulfonium p-toluenesulfonate, n-nonyl dimethyl sulfonium p-toluene sulfonate, etc., and thephosphonium salts of Carroll et a1. U.S. Patent 2,271,622, issued Feb.3, 1942, such as, tetramethylene bis-triethyl phosphonium bromide,lauryltriethyl phosphonium bromide, etc.

My light-sensitive emulsions are advantageously coated chemicallysensitized with compounds of the sulfur group, e.g., sulfur compounds ofSheppard U.S. Patent 1,574,944, and Sheppard et a1. U.S. Patents1,623,499 and 2,410,689, selenium compounds of Dunn U.S. Patent3,297,446, and McVeigh U.S. Patent 3,297,447 and tellurium compounds ofCanadian patent application 933,538, filed June 17, 1965, and chemicallysensitized with gold compounds of Waller et al. U.S. Patent 2,399,083.My silver halide emulsions advantageously contain water-soluble blockpolymers of polyoxypropylene and polyoxyethylene of Goffe U.S. Patent3,294,540 and silicon-containing polymers of Milton U.S. Patent3,294,537.

My light-sensitive emulsions are advantageously coated on any of theconventional photographic supports including glass, cellulose acetate,polystyrene, polyalkylene terephthalate, etc.

My emulsions are advantageously orthochromatically sensitized by using aspectral sensitizing dye which spectrally sensitizes in the green regionof the spectrum and produces a modicum of sensitivity in the red regionof the spectrum. My orthochromatic spectral sensitizers leave little, ifany, stain after processing. The preferred dyes are substantiallycompletely decolorized during photographic processing. By decolorizing Imean that the dye is either converted to an uncolored form by hydroxylions, sulfite ions, etc., in the processing solutions or that the dye isactually washed out of the photographic emulsion during processing. Insome instances, the decolorizing may involve both the formation of anuncolored dye and removal of the dye or uncolored dye. Included amongthe spectral sensitizing dyes used to advantage are: cyanine dyes (e.g.,cyanine dyes and complex cyanine dyes having more than two heterocyclicnuclei) in which the conventional to 6-membered basic heterocyclicnuclei are used including thiazoles, benzothiazoles, naphthothia- Zoles,oxazoles, benzoxazoles, naphthox-azoles, imidazoles, benzimidazoles,naphthimidazoles, quinoline, etc., which are unsubstituted or areadvantageously substituted with any of the conventional substituentsused on cyanine dyes including lower alkyl groups preferably having from1 to 4 carbon atoms, carboxyalkyl groups; sulfoalkyl groups,hydroxyalkyl groups, all of which preferably have from 1 to 4 carbonatoms, halogens, etc.; merocyanine dyes in which the basic nuclei aresubstituted or unsubstituted and are any of the above mentioned 5- to6-membered basic heterocyclic nuclei including in addition pyridines,indoles, tetrazoles, etc. and in which the acidic nucleus is1,3-cyclohexanedi0ne, or any of the conventional 5- to G-membered acidicheterocyclic nuclei including thiohydantoins, hydantoins, rhodanines,thiazolin-4-ones, 2-thio- 2,4-oxazolidinediones, 5-pyrazolones,barbituric acids, thiobarbituric acids, imidazoles, etc. that areunsubstituted or have substituents such as alkyl having from I to 8carbon atoms, carboxyalkyl of from 1 to 8 carbon atoms, sulfoalkyl offrom 1 to 8 carbon atoms, phenyl, sulfo phenyl, carboxyphenyl,hydroxyphenyl, carboxy, amino, dialkylaminoalkyl in which the alkylgroups have from 1 to 3 carbon atoms, etc.; holopolar dyes in which thetwo basic nuclei are any of those described above and the mesosubstituent is any of the acidic nuclei described including3,5-pyrazolidinediones, and dicyanomethyl, etc.; and oxonol dyes inwhich the acidic nuclei are any of those described herein previously andin addition include 3(2H)thianaphthenone-l,l-dioxides, and6-oxo-5,6-dihydroimidazo[2,1-b1thiazoles, etc.

Preferred representative orthochromatic sensitizing dyes used toadvantage according to my invention include the following:

(I) anhydro-5,6-dichloro-1,3'-diethy1-3-(3-sulfopropyl)benzimidazolooxacarbocyanine hydroxide (II)1,3-diethyl-6'-methyl-4,5-benzothia-2-cyanine bromide (HI)anhydro-S,5',6,6'-tetrachloro-l,l'-diethyl-3,3'-

di(3-sulfobutyl)benzimidazolocarbocyanine hydroxide (IV)3,3-diethyl-9-methyl-4,5-benzoxathiacarbocyanine iodide (V)anhydro-S-chloro-l,3'-diethyl-3-(3-sulfobutyl)benzimidazolothiacarbocyanine hydroxide (VI)1-ethyl-1'-(B-hydroxypropyl)-2,2-cyanine iodide (VII)anhydro-9-ethyl-5,5'-diphenyl-3,3-di(3-sulfobutyl)oxacarbocyaninehydroxide monosodium salt (VIII)5-(5,6-dichloro-l,3-diethyl-2-benzimidazolinylidene) -3-ethyl-2-[(3-ethyl-2-benzothiazolinylidene)methyl]-4-oxo-2-thiazolininm-p-toluenesulfonate (IX) 3-carboxymethyl-1,5-[(3-methy1-2-thiazolidinylidene)isopropylidene1rhodanine(X) 5 3-ethylnaphth [2,1-a] oxazolin-2-ylidene) ethylidene]-3-N-heptyl-1-phenyl-2-thiohydantoin (XI)5-[(3-ethyl-2-benzoxazolinylidene)ethylidene]-3-heptyl-1-phenyl-2-thiohydantoin (XII) 3-ethyl-5-{ 3- (4-sulfobutyl)-2-thiazolidinylidene]ethylidene}rhodanine, potassium salt (XIII)3-carboxymethyl-5-{ 3-ethyl-4-(paramethoxyphenyl -5-phenyl-2-4-oxazolinylidene) Jethylidene} rhodanine (XIV) Z-diphenylamino- (3-ethyl-2-benzothiazolinylidene)ethylidene] -2-thiazolin-4-one (XV)3-ethyl[ (3-ethyl-2-benzothiazolinylidene)isopropylidene]-2tl1io-2,4-oxazolidinedione (XVI)5-[(3-ethyl-2-benzoxazolinylidene)ethylidene]-3-heptyl-2-thio-2,4-oxazolidinedione (XVII)3-methyl-1-(p-sulfophenyl)-4-[ 1,3,3-trimethyl- 2-indolinylideneethylidene] -5-pyrazolone (XVIII) 4- 3-ethyl-2-benzothiazolinylidene)isopropylidene] -3-rnethyll- (p-sulfophenyl -5-pyrazolone (XIX)3-carboxy-4-[(3-ethyl-2-benzoxazolinylidene) ethylidene] -5-pyrazolone(XX) 5 (3 -ethyl-2-benzoxazolinylidene) ethylidene]3-p-hydroxyphenylrhodanine (XXI)3-carboxymethyl-5-(1-methyl-4(1H)quinoly1- idene)rhodanine (XXII) 5-(1,-B-carboxyethyl-4 lH)-pyridylidene) rhodanine (XXIII)5-{[1-(4-carboxybutyl-4-p-chlorophenyl-2-tetrazolin-S-ylidene]ethylidene}-3-ethy1rhodanine (XXIV)3-ethyl-l-phenyl-5-{[3-(4-sulfobutyl)-2-thiazoidinylidene]ethylidene}-2-thiohydantoin, potassium salt (XXV)l-(Z-diethylaminoethyl)-5-[(3-ethyl-2- benzothiazolinylidene ethylidene]-3-phenylbarbituric acid (XXVI) 3-ethyl-5-(3-ethyl-2-benzothiazolinylidene)isopropylidene]-2-methyl-4-oxo-1-phenyl-2-imidazolinium perchlorate (XXVII) 2-[1-ethy1naphtho[1,2-d]thiazolin-Z-ylidene)ethylidene]-1,3-cyclohexanedione (XXVIII) 1,3-diethyl-5-{[4,6-di(4-fluorophenyl)-lphenyl-2( 1H) -pyridylidene] ethylidene}-2-thiobarbituric acid (XXIX) 1,2-diphenyl-4-{(3-ethyl-2-benzothiazolinylidene methyl] 1-ethyl-2 1H) -quinolylidene)methyl] methylene}-3,5-pyrazolidinedione (XXX) 1,1-dicyano-2,2-di(3-ethyl-2-benzothiazolinylidene) -methyl] ethylene (XXXI)[3-ethylrhodanine (5)] [3 (2H)-thianaphthenone-1,1-dioxide- (2]methineoxonol (XXXII) [7-ethyl-6-oxo-3-phenyl-5,6-dihydroirnidazo[2,1-b] thiazolium(5) [3-ethylrhodanine(5)] methineoxonol Dyes I throughVIII are examples of cyanine dyes (dye VIII in a complex cyanine dye),dyes IX through XXVIII are examples of merocyanine dyes, dyes XXIX andXXX are holopolar dyes, and dyes XXXI and XXXII are oxonol dyes. Thesedyes are all well known in the art and are prepared by conventionalsynthesis.

The amount of the spectral sensitizing dye used to advantage can bevaried over a Wide range and will depend upon the particular emulsion,the particular dye and the effects desired. The operable and preferredamount of a given dye used advantageously to spectrally sensitize agiven silver halide emulsion is easily determined by methods well knownin the art and need not be discussed further. The dyes areadvantageously added to the silver halide emulsion as a solution inwater or other suitable solvent, such as, acetone, methanol, pyridine,etc., or mixtures of two or more of these solvents.

As mentioned before, the anthraquinone dye used as a filter dye in myphotographic elements is advantageously added to the silver halideemulsion or coated over the silver halide emulsion layer. Myanthraquinone dyes have at least one alkaline sulfomethylamino group andhave their maximum absorption in the red region of the spectrum withsubstantially no absorption of light in the blue and green regions ofthe spectrum. These dyes are water-soluble and have substantially nosensitizing effect on the photographic silver halide emulsion. Thesedyes have substantially no effect on the quality of the high contrastimages formed by development of latent images in the silver halideemulsion layers of my elements. The

anthraquinone dye is substantially completely removed from thephotographic element during photographic processing. By alkalinesulfomethylamino group I mean a group represented by the formula:

wherein M represents an alkali metal atom (e.g., sodium, potassium,etc.), ammonium (NH or organic ammonium salt group (e.g., pyridinium,triethylammonium, trimethylammonium, etc.)

The anthraquinone dyes of my invention include those having the formula:

NHCHzSOaM R R 0 R4 i R1 0 Rs H 2 wherein M is as described previously;R, R R R R and R each represents a member such as hydrogen, chlorine,bromine, hydroxyl, methyl, ethyl, propyl, methoxy,

ethoxy, propoxy, a SO M group, a NHCH SO M group, etc.

Preferred examples of anthraquinone dyes used according to my inventioninclude the following:

(A) 1,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinonetetrasodium salt (B)l,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinonetetraammonium salt (C)1,5-disulfomethylamino-3,7-disulfo-4,8-dihydroxyanthraquinonetetrapotassium salt (D) l,8-disulfomethylaminoanthraquinone disodiumsalt (E) l,8-disulfomethylamino-3,6-disulfo-4,S-dihydroxyanthraquinonetetrasodium salt (F) 1-sulfomethylamino-3-sulfo-4-hydroxyanthraquinonedisodium salt (G) 1,4-disulfomethylaminoanthraquinone disodium salt (H)1,4-disulfomethylaminoanthraquinone dipyridium salt (I)l,S-disulfomethylaminoanthraquinone disodium salt (J)1,5-disulfomethylaminoanthraquinone di-triethylammonium salt Myanthraquinone dyes are advantageously added as an aqueous solution to ahydrophilic colloid (as described before) either with or Without thesilver halide emulsion. The dyes may be used over a wide range ofconcentrations. An operable range is from about .1 gram to about 50grams per silver mole. A preferred range of concentration is from about.2 to about 20 grams per silver mole and an especially efiicaciousconcentration range is from about 1 gram to about 5 grams per silvermole. The amount of dye needed will depend upon the particular dye inquestion and the amount of the sensitivity of the silver halide emulsionin the red region of the spectrum. The optimum concentration can bedetermined readily by techniques well known in the art and need not bediscussed further herein.

The following examples are included for a further understanding of myinvention.

EXAMPLE 1 To separate portions of a fine grain silver chlorobromoiodidegelatin emulsion containing mole percent chloride, 9 mole percentbromide, 1 mole percent iodide, that is chemically sensitized with sufurand gold compounds are added the indicated spectral sensitizers at theindicated concentration (see Table 1) with and without absorbing dye A,i.e., 1,5-disulfomethylamino-3,7-disulfo- 4,8-dihydroxyanthraquinonetetrasodium salt. Each spectrally sensitized emulsion is coated on aseparate piece of a polyethylene terephthalate support at 456 mg.silver/ ft. (i.e., 4908 mg./m. 296 mg. gelatin/ft. (i.e., 3181 mg./m.and 296 mg./ft. (i.e., 3181 mg./m. of an alkyl acrylate polymer of thetype described in French Patent 1,510,222 dlivre Dec. 11, 1967. Agelatin overcoat is coated on the emulsion layer of each coating at 82.6mg./ft. 2 (i.e., 889 mg./m. After drying the fol lowing exposures aremade on each of the coatings. A sensitometric exposure to white light ismade on one area of a piece of each coating and a sensitometric exposureto red light is made on another area of each coating to determine whiteand red light speeds. On a still different unexposed area of eachcoating a safelight safety test is made by exposing through asensitometric step tablet having consecutive steps which produce 0.3 logE increments in exposure and have printed on each step an identifyingnumber for seconds to a 500 w. tungsten light source modulated by aWratten safelight series 1 filter (Eastman Kodak Company trademark anddesignation for a redcolored safelight filter) from a distance of aboutone foot (i.e., about 30.48 cm.). All the exposed coatings are developedfor 1% minutes in an amine-developer roller transport processor systemas described in Belgian Patent 704,595. After fixing with a conventionalsodium thiosulfate fixing bath, washing and drying, the contrasts,relative white light speeds and relative red light speeds are determinedfrom the processed film samples. From the last number that can be readon the developed safelight safety test step tablet image, a safelightsafety value is determined from a table. Safelight safety test values of90 and above are considered excellent, values from 45 to 90 areconsidered acceptable and values less than 45 are considered poor. Eventhough safelight safety test values of 90 are considered excellent, itis desirable to obtain higher values since they indicate that the lightsensitive material is even less sensitive to the red safelight and canbe used with more freedom under the safelight without causing fog. A netsafelight safety value is determined by normalizing the relative redlight speed to relative white light speed with the differenceillustrating that the absorbing dye results in higher red lightabsorption than blue or green light absorption. Therefore, the netsafelight safety values, when adjusted for differences in white lightspeed, result in slower red light speed 20 with the absorbing dye thanthe corresponding coating without the absorbing dye. The following Table1 summarizes the results.

Red light-absorbing dyes outside my invention such as 3methyl-4-{6-[3-(4-sulfobutyl)-2-benzoxazolinylidene]- 1,3-neopentylene2,4 hexadienylidene}-1-p-sulfophenyl- 2-pyrazolin-5-one, 3methyl-4-{6-[3-(3-sulfopropyl)-2- benzoxazolinylidene] 1,3 neopentylene2,4 hexadienylidene} 1 p sulfophenyl-Z-pyrazolin-5-one, bis[1,3-di-(S-carboxypentyl) 2 thiobarbituric acid(5)] pentamethine oxonol,bis[l-butyl 3 carboxymethylbarbituric acid(5)]pentamethine oxonol cannotbe used in place of my red light-absorbing dyes because they causedetrimental loss in the quality of the high contrast images developedfrom latent images in my silver chlorobromide emulsions. These dyes alsoproduce an undesired increase in red sensitivity in myorthochromatically sensitized silver halide emulsions.

My photographic elements provide a valuable technical advance in the artbecause they are photographically faster, because of the orthochromaticsensitization, produce excellent quality high contrast imagereproductions and because they have excellent red safelight safetyvalues.

The invention has been described in detail with particular embodimentsthereof, but it will be understood TABLE 1 Relative red light Llght-Safespeed minus sensitizing llgh re ve ing dye, safety white lightGms/Mol Dye class 2.0 g./m. Contrast value speed 16 Cyanine None. 4.2 16do A 4.8 22 Complexcyanine. None.... 7.0 22 do 7.0 Merocyani 9.0 10 do..6.9 6.9 7.4 9.0 7.5 9.9 II 10.5 XXIX 6.5 XXIX 5.5 XXX 6.2 XXX 6.1 XXXINone 7.4 XXXI 10 d0 6.5 XXXIII 13 d0 None... 6.9 2 XXXIII 13 d0 A 6.5

The even numbered coatings 2, 4, 6, 8, 10, 12, 14, 16, 18 and are of myinvention while the odd numbered coatings are outside my invention andare used for controls, for example, coating 1 is used as a control forcoating 2, coating 3 is used as a control for coating 4, etc. Theresults show that my coatings each have a substantially higher safelightsafety value than the respective control coating. Coatings 5, 7, 11 and19 outside my invention have only poor safelight safety values. Mycoatings 8, 12 and 20 have acceptable safelight safety values and mycoatings 2, 4, 6, 10, 14, 16 and 18 have excellent safelight safetyvalues. Even though coatings 1 and 3 have excellent safelight safetytest values, the addition of light absorbing dye A increased thesafelight safety test value up to 525 representing a valuable technicaladvance.

EXAMPLE 2 Example 1 is repeated using light-absorbing dyes B, C, D, E,F, G, H, I and J in place of dye A. Results similar to those obtained inmy Example 1 coatings containing dye A are obtained for each of dyes Bthrough I.

Similar results to those obtained in Examples 1 and 2 are obtained whenother fine grain silver chlorobrornoiodide gelatin emulsions are usedcontaining at least 60 mole percent chloride, less than mole percentbromide and less than about 5 mole percent iodide.

Similar results are obtained when the above examples are repeated usingother high contrast and especially lithographic developer solutions andprocesses known in the art.

that variations and modifications can be effected within the spirit andscope of the invention as described hereinabove and as defined in theappended claims.

I claim:

1. A lith-type photographic element comprising a support coated with ahydrophilic colloid layer containing a fine grain, high contrast silverhalide emulsion in which the said silver halide contains at least about60 mole percent chloride, less than about 40 mole percent bromide andless than about 5 mole percent iodide, a sensitizing dye thatorthochromatically sensitizes the said silver halide and produces amodicum of sensitivity in the red region of the spectrum, saidsensitizing dye being substantially completely decolorized duringphotographic processing, and as a filter dye for said silver halideemulsion a watersoluble anthraquinone dye having at least one alkalinesulfomethylamino group which has substantially no absorption of light inthe blue and green regions of the spectrum and which strongly absorbslight in the red region of the spectrum, and which producessubstantially no change in quality of high contrast images produced bydevelopment of latent images in the said silver halide emulsion, saidanthraquinone dye being substantially completely removed from thephotographic element during photographic processing.

2. A lith-type photographic element comprising a support coated with ahydrophilic colloid layer containing a fine grain, high contrast silverhalide emulsion in which the said silver halide contains at least about60 mole percent chloride, less than about 40 mole percent bromide andless than about mole percent iodide, a sensitizing dye selected from theclass consisting of a cyanine dye, a merocyanine dye, a holopolar dye,and an oxonol dye that orthochromatically sensitizes the said silverhalide and produces a modicum of sensitivity in the red region of thespectrum, said sensitizing dye being substantially completelydecolorized during photographic processing, and as a filter dye for saidsilver halide emulsion a watersoluble anthraquinone dye having at leastone alkaline sulfomethylamino group which has substantially noabsorption of light in the blue and green regions of the spectrum andwhich strongly absorbs light in the red region of the spectrum, andwhich produces substantially no change in quality of high contrastimages produced by development of latent images in the said silverhalide emulsion, said anthraquinone dye being substantially completelyremoved from the photographic element during photographic processing.

3. A lith-type photographic element comprising a support coated with ahydrophilic colloid layer containing a fine grain, high contrast silverhalide emulsion in which the said silver halide contains at least about60 mole percent chloride, less than about 40 mol percent bromide andless than about 5 mole percent iodide, a merocyanine sensitizing dyethat orthochromatically sensitizes the said silver halide and produces amodicum of sensitivity in the red region of the spectrum, saidsensitizing dye being substantially completely decolorized duringphotographic processing, and as a filter dye for said silver halideemulsion a water'soluble anthraquinone dye having at least one alkalinesulfomethylamino group which has substantially no absorption of light inthe blue and green regions of the spectrum and which strongly absorbslight in the red region of the spectrum, and which producessubstantially no change in quality of high contrast images produced bydevelopment of latent images in the said silver halide emulsion, saidanthraquinone dye being substantially completely removed from thephotographic element during photographic processing.

4. A lith-type photographic element comprising a support coated with ahydrophilic colloid layer containing a fine grain, high contrast silverhalide emulsion in which the said silver halide contains at least about60 mole percent chloride, less than about 40 mole percent bromide andless than about 5 mole percent iodide, an acid substituted merocyaninesensitizing dye that orthochromatically sensitizes the said silverhalide and produces a modicum of sensitivity in the red region of thespectrum, said sensitizing dye being substantially completelydecolorized during photographic processing, and as a filter dye for saidsilver halide emulsion a water-soluble anthraquinone dye having at leastone alkaline sulfomethylamino group which has substantially noabsorption of light in the blue and green regions of the spectrum andwhich strongly absorbs light in the red region of the spectrum, andwhich produces substantially no change in quality of high contrastimages produced by development of latent images in the said silverhalide emulsion, said anthraquinone dye being substantially completelyremoved from the photographic element during photographic processing.

5. A photographic element of claim 4 in which the said merocyanine dyecontains a rhodanine nucleus.

6. A photographic element of claim 4 in which the said merocyanine dyecontains a thiohydantoin nucleus.

7. A photographic element of said claim 2 in which the saidanthraquinone dye is in a hydrophilic colloid layer coated over thehydrophilic colloid layer containing the said silver halide emulsion.

8. A photographic element of claim 2 in which the said anthraquinone dyeis in the same hydrophilic colloid layer that contains the said silverhalide emulsion.

9. A photographic element of claim 2 in which the said anthraquinone dyeis represented by the formula:

0 NHOHzSOsM R5 H R 0 C B5 II R2 wherein M represents a member selectedfrom the class consisting of an alkali metal atom, the ammonium group,and an organic ammonium salt group; R, R R R R and R each represents amember selected from the class consisting of hydrogen, chlorine,bromine, the hydroxyl group, methyl, ethyl, methoxy, ethoxy, a SO Mgroup and a -NHCH SO M group.

10. A photographic element of claim 2 in which the said sensitizing dyeis anhydro-5,6-dichloro-1,3'-diethyl-3-(3-sulfopropyl)benzimidazolooxacarbocyanine hydroxide.

11. A photographic element of claim 2 in which the said sensitizing dyeis 1,2-diphenyl-4-{[(3-ethyl-2-benzothiazolinylidene)methyl][(l ethyl2(1H) quinolylidene)methyl]methylene}-3,S-pyrazolidinedione.

12. A photographic element of claim 2 in which the said sensitizing dyeis 3-carboXymethyl-l,5-[(3-methyl-2-thiazolidinylidine)isopropylidene]rhodanine.

13. A photographic element of claim 2 in which the said sensitizing dyeis 5-[ (3-ethylnaphth[2,1-a] oXazolin-2- ylidene)ethylidene] 3 Nheptyl-1-phenyl-2-thiohydantoin.

14. A photographic element of claim 2 in which the said sensitizing dyeis 5-[(3-ethyl-2-benzoxazolinylidene) ethylidene]-3-heptyl-1-phenyl-2-thiohydantoin.

15. A photographic element of claim 2 in which the said sensitizing dyeis3-ethyl-5-{[3-(4-sulfobutyl)-2-thiaazolidinylidene]ethylidene}rhodanine,potassium salt.

16. A photographic element of claim 3 in which the said anthraquinonedye has at least one alkaline sultomethylamino group.

References Cited UNITED STATES PATENTS 2,456,956 12/1948 Knott et al.96-64 2,622,082 12/ 1952 Sprague 260--240.9X 2,865,752 12/1958 Saunderset al. 96l02 NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO,Assistant Examiner US. Cl. X.R. 96106

